This is the way that I've lived my whole life. I've never been on a diet, ever, and I've never been overweight, ever (except for short periods after Thanksgiving or when I return from a vacation to Germany and Italy). I've never felt the need to eat when I'm not hungry and so I don't.
It's all perfectly logical and relates to the concept of satiety, the pleasure gained from eating good-tasting food.
Moderation is the key, and that's the important underlying message. No gorging, no unnatural fixations on eating calorie-free foods when they taste lousy and are ultimately unsatisfying.
I don't exercise excessively, and it's been working fine for me for the past 40 years.
It's the stopping when you are full that is the key. I cannot eat past fullness, and I have never had a weight problem. I don't even own a scale. But most people seem to be able to keep eating past the point of fullness, and that's how they get fat. And once you get fat, it's hard to lose weight, since fat is the body's long term energy storage system.
I often wish I could eat more than I can, that is for sure.